With the improvement of living standards, people are placing more and more emphasis on outdoor recreational activities, some common examples of which are mountaineering and cycling. Take mountaineering for example. It is not unusual that a mountaineer carries a folding knife with them to chop or cut off prickly shrubs or branches. A commercially available folding knife is typically composed of a handle and a blade, wherein the blade is pivotally connected to the handle so as to spin out of or fold into the handle. Once the blade is rotated out of the handle, the folding knife is ready for chopping or cutting. However, according to years of observation by the present inventor, the blade is very likely to rotate back into the handle automatically during use if the force applied by the user to the folding knife is too large or is at an inappropriate angle. Should the blade fold into the blade under such circumstances, the user's hand may be cut, which is highly dangerous.
To address the safety issue of the conventional folding knives, structural improvements have been made to bring about a folding knife with an elastic stop plate as shown in FIG. 1. The improved folding knife 1 includes a handle 10 and a plate element 10a disposed therein. The plate element 10a is provided with an elastic stop plate 11. A blade 12 is pivotally connected to one side of the plate element 10a and can be rotated into and out of the handle 10. Once the blade 12 is folded in the handle 10, the elastic stop plate 11 presses against a lateral side of the blade 12 resiliently, thanks to the elasticity of the elastic stop plate 11. As soon as the blade 12 is rotated, or springs, out of the handle 10, the free end of the elastic stop plate 11 (i.e., the lower right end as shown in FIG. 1) moves elastically toward the blade 12. More specifically, the free end of the elastic stop plate 11 will move to a position adjacent to one end of the blade 12 (i.e., the end away from the blade tip) and press against the blade 12, as shown in FIG. 1.
In the state shown in FIG. 1, the blade 12, which is pressed against by the elastic stop plate 11, cannot fold easily into the handle 10. Even if the user attempts to rotate the blade 12 into the handle 10, the elastic stop plate 11 pressing against the blade 12 will prevent the attempt from succeeding. If the user really wants to fold the blade 12, it is required to press the elastic stop plate 11 first so that the elastic stop plate 11 is moved away from the position where it can press against the blade 12. Only then can the blade 12 be rotated by the user. However, when the user holds the folding knife 1 by the handle 10 and performs a thrusting or chopping action with an excessively large force or at an improper angle, the resulting shocks or other reaction forces may also drive the elastic stop plate 11 away from the position where it can press against the blade 12. Should this happen, the blade 12 will rotate toward the handle 10 instantaneously and may thus injure the user's hand. It can be known from the above that both the conventional folding knives and the improved ones are not safe enough and therefore cannot be used with peace of mind. Moreover, neither the conventional nor the improved folding knives provide a reliable locking mechanism for locking the blade in the folded state. In the absence of such a locking mechanism, the blade in the folded state may, when activated or pushed out inadvertently, spin or spring out of the handle and injure the user as a result.
Hence, the issue to be addressed by the present invention is to overcome the various drawbacks of the existing folding knives and design a folding knife with a locking mechanism. It is desirable that the locking mechanism can lock the blade of the folding knife in the folded state as well as in the opened state, thus enhancing the safety and convenience of use of the folding knife.